Porifera or sponges is a phylum that includes all simple primitive aquatic animals, distinguished by having a body full of channels and pores through which water flows. Sponges are formed by sets of cells that arrange in spicules which provide sponges a structure and spongin which is a protein. Additionally, sponges lack organs and are asymmetrical which means they have an irregular shape. Moreover, they stand out for having a great diversity of color and their sizes are varied from a few millimeters to more than 2 m high. So, the correct answer is D. Porifera.
The most important abiotic factors include water, sunlight, oxygen, soil and temperature. Water (H2O) is a very important abiotic factor – it is often said that “water is life.” All living organisms need water.
